"The most common mode of analysis in economic theory is to assume equilibrium. Yet, without a proper theory of how economies behave in disequilibrium, there is no foundation for such a practice. The necessary step in proposing a foundation is the formulation of a theory of stability, and Professor Fisher is primarily concerned with this subject, although disequilibrium behavior itself is analyzed. The author first undertakes a review of the existing literature on the stability of general equilibrium. He then proposes a more satisfactory general model in which agents realize their state of disequilibrium and act on arbitrage opportunities. The interrelated topics of the role of money, the nature of quantity constraints, and the optimal behaviour of arbitraging agents are extensively treated."

"In economics, most noncooperative game theory has focused on equilibrium in games, especially Nash equilibrium and its refinements. The traditional explanation for when and why equilibrium arises is that it results from analysis and introspection by the players in a situation where the rules of the game, the rationality of the players, and the players' payoff functions are all common knowledge. Both conceptually and empirically, this theory has many problems.

In The Theory of Learning in Games Drew Fudenberg and David Levine develop an alternative explanation that equilibrium arises as the long-run outcome of a process in which less than fully rational players grope for optimality over time. The models they explore provide a foundation for equilibrium theory and suggest useful ways for economists to evaluate and modify traditional equilibrium concepts."